Forming apparatus



Dec. 17, 1963 D. F. BROWER ETAL 3, ,585

FORMING APPARATUS Filed Feb. 6. 1962 2 Sheets-Sheet 1 Dec. 17, 1963 D. F. BROWER ETAL 3, ,585

FORMING APPARATUS Filed Feb. 6, 1962 jjg 116 75 5 2 Sheets-Sheet 2 I if f5 United States Patent Ofifice 3,114,585 Patented Dec. 17, 1963 3,114,585 FDRMING APPARATUS David F. Brewer, San Diego, and Gannon B. Hayward, La Jolla (San Diego), Calif, assignors to General Dynamics Corporation, New York, N.Y., a corporation of Delaware Filed Feb. 6, 1962, Ser. No. 171,383 Claims. (Cl. 33914) relates to a forming apparatus a forming apparatus in which magnetic field is employed to amperage through the conductor. The high density field induces a current in a conductive work piece disposed in the magnetic field. The interaction between the high density magnetic field and the magnetic field produced by the induced current in the work piece produces an impulse on the work piece which, when made great enough, forms the work piece.

The shape of the conductor employed with such apparatus depends upon the shape of the work piece and the desired end product. Because it is desirable to accomplish diverse forming operations with a single forming apparatus, the apparatus is thus preferably designed to accommodate various sizes and shapes of conductors. Also, it is desirable that the apparatus be designed so that the shaped conductor is easily and quickly clamped in position on the apparatus and, at the sametime, electrical connections are made to the shaped conductor. Moreover, since high currents are employed in the forming apparatus, it is desirable to isolate or ground the the operator of the apparatus.

An object of the present invention is the provision of a magnetic forming apparatus which incorporates one or more of the above features. Another object of the invention is the provision of a magnetic forming apparatus which includes a clamping device that clamps a shaped conductor in position on the apparatus and, at the same time, makes electrical connections to the shaped conductor. Still another object is the provision of a clamping device for a magnetic forming apparatus. A further object is the provision of a shaped conductor assembly which is provided with a bracket for mounting the same in a magnetic forming apparatus. Still a further object is the provision of a forming apparatus which includes a clamping device for quickly and easily clamping a shaped conductor assembly on the apparatus, which clamping device is relatively inexpensive to manufacture and durable in use.

Other objects and advantages of the present invention will become apparent with reference to the following description and accompanying drawings:

In the drawings:

FIGURE 1 is a perspective view of a clamping device and a shaped conductor assembly in accordance with the present invention, the clamping device being mounted on a top plate of a forming apparatus, and the shaped conductor assembly being shown in spaced relation to the clamping device;

FIGURE 2 is an enlarged plan view of the shaped conductor assembly and clamping device shown in FIG- URE 1, with the shaped conductor assembly being shown clamped in position on the forming apparatus;

FIGURE 3 is a side view of the shaped conductor assembly and clamping device shown in FIGURE 2 with portions being broken away to better illustrate certain features thereof;

FIGURE 4 is an enlarged cross-sectional view taken generally along line 44 of FIGURE 2.;

FIGURE 5. is a cross-sectional view taken generally along lines 5-5 of FIGURE 4;

FIGURE 6 is an exploded view of the clamping device shovm in FIGURES 1 through 5; and

FIGURE 7 is a perspective view of one of the parts of the clamping device shown in FIGURES 1 to 6.

Generally, in accordance with the present invention, a device is provided for clamping a shaped conductor assembly in position on a magnetic forming apparatus and, at the same time, connecting the ends of a shaped conductor in the assembly, respectively to a high amperage terminal and a ground terminal in the apparatus. The shaped conductor assembly is provided with a mounting bracket having a pair of opposed, mutually insulated conductive faces. One end of the shaped conductor is connected to one of the faces and the other end of the shaped conductor is connected to the other face, whereby the conductive faces of the bracket serve as terminals for the shaped conductor.

The clamping device includes a stationary jaw member fixedly mounted on the forming apparatus and a movable jaw member movably mounted on the forming apparatus for movement between an open position, wherein the bracket of the shaped conductor assembly may be disposed between the stationary jaw member and the movable jaw member, and a closed position, wherein the bracket is clamped between the movable jaw member and the stationary jaw member. The portions of the stationary jaw member and the movable jaw member which are in contact with the faces of the bracket are made of conductive material and are coupled, respectively, to the high amperage terminal and the ground terminal of the forming apparatus. Thus, when the shaped conductor assembly is clamped in position, the ends of the shaped conductor are coupled to the high amperage terminal and the ground terminal.

More specifically, as shown particularly in FIGURES 1 and 2, a shaped conductor assembly 8 is clamped in position on a forming apparatus by a clamping device 10. The clamping device 10 is fixedly mounted on a hori zontally extending work surface 12 of a cabinet 14 of the magnetic forming apparatus. The cabinet 14 houses operating controls (not shown) and a source of high amperage current pulses (not shown). The construction of the cabinet 14, the operating controls, and the source are not important features of this invention and therefore are not described in detail. A suitable source and control circuit is shown in Patent No. 2,976,907.

As shown in FIGURE 6, the work surface 12, which is formed by a pair of superimposed plates 18 and 20, is provided with a generally rectangular aperture 22 which is adapted to receive a mounting means 24 for the clamping device 10. The mounting means 24 is in the form of a generally rectangular block of insulating material and is disposed within the aperture 22 with a portion thereof extending above the work surface 12. The mounting block 24 is provided with flanges 26 along the opposite long sides thereof whereby the block 24 is fastened to the lower plate 18 of the work surface 12 by suitable means, such as screws 28 which extend through apertures 30 in the lower plate 18 and are threadedly engaged with the mounting block 24.

As shown particularly in FIGURES 4 and 6, the mounting block 24 includes an elongated and generally rectangular high voltage insert 34 of conductive material. The insert 34 is fixedly secured in a corresponding slot 36 in the block 24 which slot extends parallel to one of the long sides of the aperture 22 and in spaced relation thereto. The high voltage insert 34 is of sufiicient height to extend vertically through and slightly beyond the surface of the block 24.

A generally rectangular ground insert 38 of conductive material is fixedly mounted within a corresponding slot 49 in the mounting block 24- which slot extends horizontally from a position spaced from the high voltage insert to a position under the work surface 12 of the forming apparatus. The portion of the ground insert 38 under the work surface 12 receives the screws 28 which fasten the mounting block 24 to the same, whereby the ground insert 38 is electrically connected to the work surface 12 of the forming apparatus.

As shown in FIGURE 4, a high voltage conductor 42 in the form of an L-shaped strip of conductive material, is fastened to the lower surface of the high voltage insert 34 by suitable means, such as screws 44. A grounding conductor 46 of a similar construction to the high voltage conductor 42 is fastened to the ground insert 38. The upper and lower surfaces of the mounting block 24 between the high voltage insert 34 and the ground insert 38 are each provided with a pair of horizontally extending ribs 48 that form a barrier between the high voltage and ground inserts 34 and 38.

In the illustrated embodiment, a stationary member 50 of structural and conductive material such as brass, is mounted on the mounting block 24. As shown particularly in FIGURE 1, the stationary member 50 includes a hollow generally rectangular base portion 52 and a generally U-shaped upper portion 54. The legs 56 and 58 of the U-shaped portion 54 extend generally horizontally and are terminated at a distance from one side of the base portion 52. The base portion 52 is made larger than the aperture 22 and is disposed on the mounting block 24 so that one leg 56 of the U-shaped portion 54 extends along the ground insert 38 and the other leg 58 is spaced from the high voltage insert 34. As will be described hereinafter, the one leg 56 serves as a stationary jaw member of the clamping device. The lower surface of the base portion 52 is suitably recessed to receive the projecting portion of the mounting block 24.

The stationary member 50 is fastened to the mounting block 24 by suitable means such as screws 60 which extend through the one leg 56 of the U-shaped portion 54 into threaded holes in the ground insert 38, the stationary member 50 thereby being grounded. In the illustrated embodiment four screws 60 are provided and these are staggered to provide a firmer mounting of the sationary member 50.

In the illustrated embodiment, a movable jaw member 62 is disposed in the hollow center portion of the stationary member 50. As shown particularly in FIG- URE 4, the movable jaw member 62 includes a vertically extending, generally rectangular block 64 of insulating material, and a generally L-shaped strip 66 of conductive and resilient material such as beryllium copper. A generally vertically extending leg of the strip 66 is disposed in a recess 68 in the face of the block 64 and a horizontally extending leg thereof is fastened to the upper surface of the high voltage insert 34 by suitable means, such as screws 69. The lower surface of the insulating block 64 is provided with a recess 70 which is of sufficient size to allow movement of the block relative to the mounting screws 68 of the L-shaped strip 66.

In the illustrated embodiment, the movable jaw member 62 is moved to a clamping position and to an open position by a horizontally extending clamp bolt 72 which extends through the other leg 58 of the U-shaped upper portion 54 and is threadedly engaged therein. The inner end of the clamp bolt 72 is rotatably held in a clamp pad 74 which bears against the surface of the movable jaw member 62. A suitable handle 76 is provided on the outer end of the clamp bolt 72 to facilitate turning of the same. The movable jaw member 62 is biased toward the clamp pad 74 by the strip 66 which is formed so that the upwardly extending leg thereof tends to assume a slanted position relative to the mounting block 24.

As previously indicated, the clamping device 10 is employed to clamp a shaped conductor assembly into position on the forming apparatus. The shaped conductor assembly may include various sizes and shapes of conductors, depending upon the operation to be performed by the forming apparatus. For example, the shaped conductor assembly may include a conductor which is generally pancake shaped, hairpin shaped, spirally shaped, solenoid shaped, etc. Also, the shaped conductor assembly may include a flux concentrator for concentrating the flux applied to a work piece. The particular shape and construction of the shaped conductor and its housing are not important features of the present invention and are not described in detail.

In the illustrated embodiment, a shaped conductor assembly 8 is shown which is employed to reduce the crosssection of a tubular work piece. As shown particularly in FIGURE 3, the shaped conductor assembly 8 includes a conductor 78 which is formed into the shape of a solenoid and is encompassed by insulating and structural material 80 such as fiber glass roving. The insulated solenoid 78 is encased in an annular housing 82 of conductive material, which housing 82 is provided with a slot 84 extending from the outer surface thereof to the inner surface thereof.

As shown in FIGURES 1 to 3, a fiux concentrating means '86 in the form of a generally cylindrical core of conductive material having a flanged upper portion is disposed within the annular housing 82. The core 86 is suitably insulated from the housing 82 and is fastened therein by suitable means. The core 86 is provided with a central aperture 88 for receiving a work piece to be formed and a slot 90 which forms an extension of the slot 84 in the housing. The slot 84 is prevented from spreading by a structural member 92 of insulating material which spans the slot 84 and is fastened to the housing by suitable means.

The shaped conductor assembly 8 is supported within the clamping device 10 by a vertically extending, generally flat, rectangular mounting bracket 94. As shown in FIGURE 2, the mounting bracket 94, which is of laminated construction, is connected to the housing 82 by an integral extension 96 of a relatively thick outer layer 98 of the bracket 94, which layer 98 is made of structural and conductive material such as brass. The extension 96 is curved to correspond to the housing 82 and is suitably mounted to the housing 82.

The outer face of the outer layer 98 is provided with a generally circular projection 100 which is adapted to be received in a generally vertically extending slot 102 in the wall of the stationary jaw member 56. The projec tion 100 thereby serves as a positioning lug for the shaped conductor assembly.

In the illustrated embodiment, the lower end (not shown) of the shaped conductor 78 is suit-ably connected to the extension 96 of the structural layer 98. Thus, when the mounting bracket 94 is disposed within the clamping device 10 and is clamped in place, the structural layer 98 bears against the stationary jaw member 56 and thereby serves as a means for connecting one end of the conductor 78 to the grounding conductor 46 of the high amperage source.

As shown in FIGURES 4 and 5, the upper end portion 104 of the conductor 78 extends generally horizontally along the inner face of the structural layer 98 and is insulated from the structural layer 98 by a layer 106 of insulating material. The upper end portion 104 of the conductor 78 is suitably connected, as by soldering, to the upper end of a vertically extending strip 108 of conductive material. The major portion of the strip 108 is disposed between a generally rectangular backing member 110 and a coextensive contact member 112. The

contact member 112 is fastened to the backing member 110 by suitable means, such as screws.

The strip 108, the backing member 110, and the contact member 112 are retained in position in the mounting bracket 94 by coextensiv'eframing layers 114and 116 of insulating material. In this connection, the portions of the strip 108 which extend beyond the contact and backing members 112 and 110 are disposed between the framing layers 114 and 116which are suitably fastened to the structural layer 98; The combined thickness of the backing member 110, the strip 108 and the contact member 112 is such that the contact member 112 extends beyond the outer surface of the frame member 116. In this way, good contact is made with the L-shaped strip 66 in the movable jaw'member 62 andthus with the high voltage conductor 42.

To clamp the shaped conductor assembly in position, the conductor assembly 8 is inserted between the movable jaw member 62 and the stationary jaw member 56 with the locating lug 100' disposed in the slot 102. The clamping bolt 72 is then rotated to cause the movable jaw member 62 to press the mounting bracket 94 against the stationary jaw member 56. In this way, the structural layer 98 of the mounting bracket 94 makes good electrical contact with the grounded stationary jaw member 56' and the contact member 112 makes good electrical contact with the conductive strip 66 and thus with the highvoltage conductor 42. At the same time, the shaped conductor assembly 8'is clamped in position on the forming apparatus. The shaped conductor assembly may also be mounted vertically, that is, with the apering said movable jaw member to said open position and to said closed position, means coupling said one stationary member to said ground conductor, and means coupling said contact to "said high voltage conductor.

2. In a magnetic forming apparatus, a device for clamping a shaped conductor assembly in position on a work surface of the apparatus and at the same time, connecting the ends of a shaped conductor in said assembly, respectively, to a high voltage conductor and a ground conductor in the apparatus, said shaped conductor being provided with a flat mounting bracket having a pair of opposed conductive faces which are insulated from each other, one end of the shaped conductor being connected to one of the faces and the other end of the conductor being connected to the other face, said device comprising a U-shaped member of conductive material fixedly mounted on said apparatus, means for connecting said stationary member to the ground conductor, a movable jaw member of insulating material disposed between the legs of said U-shaped member, said jaw member including a contact of conductive material ina side thereof which faces one of the legs of the U-shaped member, means for connecting said contact to said high voltage conductor, said jaw member being mounted on said apparatus for movement between an open position wherein the bracket may be disposed betweenthe contact and said one leg of the U shaped member, and a closed position wherein the bracket is clamped between said contact and said one leg, and means engaging said other leg of said U-shaped member and said jaw member for moving said jaw member to said closed position and to said open position.

ture 88 in the core 86 extending horizontally. To release the shaped conductor assembly 8, the clamping bolt is rotated, thereby permittingthe resilience of the conductive strip 66 to move the movable jaw member 62 away from the stationary jaw member 56. The shaped conductor assembly -8 may then be removed from the clamping device 10.

As can be seen from the above, the parts of the clamping device and the shaped conductor assembly that have high voltage applied thereto are insulated or are at ground potential. Moreover, the clamping device readily and easily clamps the shaped conductor in position in the forming apparatus and, at the same time, makes electrical connections to the shaped conductor.

Various changes and modifications may be made in the above described forming apparatus without deviating from the spirit or scope of the present invention.

Various of the features of the present invention are set forth in the accompanying claims.

We claim:

1. In a magnetic forming apparatus, a device for clamping a shaped conductor assembly in position on the apparatus and at the same time connecting the ends of a shaped conductor in said assembly, respectively, to a high voltage conductor and a ground conductor in the apparatus, said shaped conductor being provided with a mounting bracket having a pair of mutually insulated opposed conductive faces, one end of the shaped conductor being coupled to one of the faces and the other end of the shaped conductor being coupled to the other face, said device comprising a pair of spaced apart stationary members fixedly mounted on said apparatus, one of said stationary members being of conductive material, a movable jaw member of insulating material movably mounted on the apparatus between said stationary members for movement between an open position wherein the bracket may be disposed between said one stationary member and said movable jaw member, and a closed position wherein the bracket is clamped in position between said one stationary member and said movable jaw member, said movable jaw member including a contact of conductive materialin a side thereof which faces said one stationary member, means connected to said movable jaw member and to said other stationary member for mov- 3. In a magnetic forming apparatus, a device for clamping a shaped conductor assembly in position on a work surface of the apparatus and, at the same time, connecting the ends of a shaped conductor, respectively, to a high voltage conductor and a ground conductor in the apparatus, said shaped conductor being provided with a flat mounting bracket having a pair of opposed conductive faces which are insulated from each other, one end of the shaped conductor being connected to one of the faces and the other end of the shaped conductor being connected to the other face, said device comprising a U-shaped member fixedly mounted on said apparatus, means for connecting said stationary member to the ground conductor, a movable jaw member of insulating material disposed between the legs of said U-shaped member, said jaw member including a contact of conductive material in a side thereof which faces one of the legs of the U-shaped member, means for connecting said insert to said high voltage conductor, said jaw member being mounted on said apparatus for movement between an open position wherein the bracket may be disposed between the contact and said one leg of the U-shaped member, and a closed position wherein the extension is clamped between said contact and said one leg, and a bolt threadedly engaged in the other leg of said U-shaped member and being rotatably connected to the opposed side of the jaw member, whereby said bolt may be rotated to move said movable jaw member to said closed position and to said open position.

4. In a magnetic forming apparatus, a device for clamping a shaped conductor assembly in position on a horizontally extending work surface of the apparatus and, at the same time, connecting the ends of a shaped conductor in said assembly, respectively, to a high voltage conductor and a ground conductor in the apparatus, said shaped conductor being provided with a flat mounting bracket having a pair of opposed conductive faces which are insulated from each other, one of said faces including a projection, one end of the shaped conductor being connected to one of the faces and the other end of the shaped conductor being connected to the other face, said device comprising a U-shaped member of conductive material fixedly mounted on said apparatus with the legs thereof extendin-g parallel to the work surface, means coupling said member to the ground conductor, a movable jaw member of insulating material disposed between the legs of said U-shaped member, said jaw member including a contact of conductive material in a side thereof which faces one of said legs of said U-shaped member, the side of said leg facing said contact being provided with a vertically extending slot adapted to receive said projection, means coupling said contact to the high voltage conductor, said movable jaw member being mounted on said Work surface for movement between an open position wherein the bracket may be disposed between the contact and said one leg, and a closed position wherein the bracket is clamped between said contact and said one leg, and a bolt threadedly engaged in the other leg of said U-shaped member and being rotatably connected to the opposed side of the jaw member, whereby said bolt may be rotated to move said jaw member to said closed position and to said open position.

5. In a magnetic forming apparatus, the combination of a shaped conductor assembly including a shaped conductor, and a device for clamping said shaped conductor assembly in position on a horizontally extending work surface of the apparatus and, at the same time, connecting the ends of said shaped conductor, respectively, to a high voltage conductor and a ground conductor in the apparatus, said shaped conductor assembly including a flat mounting bracket of conductive material, a contact member of conductive material in one face of said bracket, means insulating said contact member from said bracket, one end of the shaped conductor being coupled to said bracket and the other end of the shaped conductor being coupled to the contact member, and a projection on the other face of said bracket, said device comprising a U-shaped member of conductive material fixedly mounted on said apparatus with the legs thereof extending parallel to the work surface, means coupling said U-shaped member to the ground conductor, a movable jaw member of insulating material disposed between the legs of said U-shaped member, said movable jaw member including a contact of conductive material in a side thereof which faces one of said legs of said U-shaped member, the side of said leg facing said contact being provided with a vertically extending slot adapted to receive said projection, means coupling said contact to the high voltage conductor, said movable member being mounted on said apparatus for movement between an open position wherein the bracket may be disposed between the contact and said one leg, and a closed position wherein the bracket is clamped between said contact and said one leg, and a bolt threaded-1y engaged in the other leg of said U-shaped member and being rotatably connected to the opposed side of the movable jaw member, whereby said bolt may be rotated to move said movable jaw member to said closed position and to said open position.

References Cited in the file of this patent UNITED STATES PATENTS 403,308 Thompson May 14, 1889 1,162,996 Farrelly et al Dec. 7, 1915 2,175,883 De Reamer Oct. 10, 1939 2,220,810 Bright Nov. 5, 1940 2,289,172 Beal July 7, 1942 2,353,114 Novak July 4, 1944 2,522,810 Bailey Sept. 19, 1950 2,632,068 Froebel et al Mar. 17, 1953 2,793,355 Randall et al May 21, 1957 2,976,907 Harvey et al Mar. 28, 1961 

1. IN A MAGNETIC FORMING APPARATUS, A DEVICE FOR CLAMPING A SHAPED CONDUCTOR ASSEMBLY IN POSITION ON THE APPARATUS AND AT THE SAME TIME CONNECTING THE ENDS OF A SHAPED CONDUCTOR IN SAID ASSEMBLY, RESPECTIVELY, TO A HIGH VOLTAGE CONDUCTOR AND A GROUND CONDUCTOR IN THE APPARATUS, SAID SHAPED CONDUCTOR BEING PROVIDED WITH A MOUNTING BRACKET HAVING A PAIR OF MUTUALLY INSULATED OPPOSED CONDUCTIVE FACES, ONE END OF THE SHAPED CONDUCTOR BEING COUPLED TO ONE OF THE FACES AND THE OTHER END OF THE SHAPED CONDUCTOR BEING COUPLED TO THE OTHER FACE, SAID DEVICE COMPRISING A PAIR OF SPACED APART STATIONARY MEMBERS FIXEDLY MOUNTED ON SAID APPARATUS, ONE OF SAID STATIONARY MEMBERS BEING OF CONDUCTIVE MATERIAL, A MOVABLE JAW MEMBER OF INSULATING MATERIAL MOVABLY MOUNTED ON THE APPARATUS BETWEEN SAID STATIONARY MEMBERS FOR MOVEMENT BETWEEN AN OPEN POSITION WHEREIN THE BRACKET MAY BE DISPOSED BETWEEN SAID ONE STATIONARY MEMBER AND SAID MOVABLE JAW MEMBER, AND A CLOSED POSITION WHEREIN THE BRACKET IS CLAMPED IN POSITION BETWEEN SAID ONE STATIONARY MEMBER AND SAID MOVABLE JAW MEMBER, SAID MOVABLE JAW MEMBER INCLUDING A CONTACT OF CONDUCTIVE MATERIAL IN A SIDE THEREOF WHICH FACES SAID ONE STATIONARY MEMBER, MEANS CONNECTED TO SAID MOVABLE JAW MEMBER AND TO SAID OTHER STATIONARY MEMBER FOR MOVING SAID MOVABLE JAW MEMBER TO SAID OPEN POSITION AND TO SAID CLOSED POSITION, MEANS COUPLING SAID ONE STATIONARY MEMBER TO SAID GROUND CONDUCTOR, AND MEANS COUPLING SAID CONTACT TO SAID HIGH VOLTAGE CONDUCTOR. 